Linq加入哪里？

Question

• entity1 - ID,OwnerCode
  • entity2 - OwnerCode,DepartmentCode

我也有一些DepartmentCode

现在我想得到这样的东西(sql语法):

Select e1.ID 
from entity1 e1 
join entity2 e2 on e1.OwnerCode = e2.OwnerCode and e2.DepartmentCode=7

通过Linq

我写:

var q = from e1 in entityes1 
        join e2 in entityes2 on e1.OwnerCode equals e2.OwnerCode ... 

但是如何插入DepartmentCode = 7这里我不明白.

Answer 1

这并不是加入表格的真正因素,它是选择记录的一个因素,因此它应该是一个where子句:

var q = from e1 in entityes1
        join e2 in entityes2 on e1.OwnerCode equals e2.OwnerCode
        where e2.DepartmentCode == 7
        select e1.ID;

var id = q.Single();